Pathology of Restrictive Lung Disease

Question 1

What is the interstitium?

Answer 1

The connective tissue space around the airways and vessels and the space between the basement membranes of the alveolar walls

Question 2

What are the two basement membranes in the alveoli?

Answer 2

Alveolar epithelial (pneumocyte)
Interstitial capillary endothelial cell

Question 3

Describe the relationship between the two basement membranes in the alveoli.

Answer 3

Usually in direct contact

Question 4

What is found in the usual interstitium?

Answer 4

Elastic fibres and the occasional cell, like a fibroblast

Question 5

Discuss the pathology of the interstitium in lung disease.

Answer 5

It becomes thickened due to a space between the two basement membranes

Question 6

Why is the thickening of the interstitium an issue?

Answer 6

Makes it more difficult for the diffusion of gases.

Question 7

What happens to the lungs due to the inflammatory process due to the thickening of the interstitium?

Answer 7

They become rigid and stiff

Question 8

What happens to FEV1 and FVC and the ratio between the two when the elastic tissue in the lungs loses it’s elasticity?

Answer 8

Low FEV1 & Low FVC but FEV1/FVC normal ratio

Question 9

What may happen to perfusion/ventilation when the small airways are affected by pathology?

Answer 9

There is an imbalance between perfusion and ventilation

Question 10

Describe what a patient may present with if they have a restrictive lung disease.

Answer 10

Dyspnoea- SOB on exertion (would have to abnormal for that person).

Question 11

As the disease progresses, what may happen to the symptoms of a patient w restrictive lung disease?

Answer 11

SOB on exertion will g to SOB at rest

Question 12

What may patients with restrictive lung disease develop?

Answer 12

Type 1 respiratory failure
Heart failure

Question 13

What is the difference between type 1 and 2 respiratory failure?

Answer 13

Type 1 respiratory failure- the respiratory system cannot adequately provide oxygen to the body.
Type 2 respiratory failure-respiratory system cannot sufficiently remove carbon dioxide from the body.

Question 14

What can type 1 respiratory failure lead to?

Answer 14

Hypoxemia

Question 15

What can type 2 respiratory failure lead to?

Answer 15

Hypercapnia -> too much CO2 in the bloodstream

Question 16

What does a CXR of someone with interstitial lung disease show?

Answer 16

Reduced lung volumes and increased lung markings

Question 17

What can a chronic inflammatory response involve the formation of?

Answer 17

Granulomas

Question 18

What can diffuse alveolar damage be associated with?

Answer 18

-Major trauma
-Chemical injury / toxic inhalation
-Circulatory shock
-Drugs
-Infection incl viruses
-Auto(immune) disease
-Radiation

Question 19

Name some of the viruses which can cause death due to DADS (diffuse alveolar damage syndrome).

Answer 19

Influenza
SARS Cov1 aka covid
SARS Cov2 aka covid

Question 20

What are most people with DADS going to end up with?

Answer 20

Type 1 respiratory failure- often life threatening

Question 21

What happens to cells in DADS to try and attempt to repair the fluid filled alveoli?

Answer 21

Proliferation of type 2 pneumocytes
Proliferation of fibroblasts

Question 22

What happens to the lungs as result of DADS?

Answer 22

Scarred, solid lungs

Question 23

Name two types of chronic granulomatous response.

Answer 23

Sarcoidosis
Hypersensitivity pneumonitis

Question 24

What is sarcoidosis?

Answer 24

A multisystem granulomatous disorder

Question 25

What causes sarcoidosis?

Answer 25

Uknown

Question 26

Which parts of the body are very likely to be affected by sarcoidosis?

Answer 26

Lymph nodes Lungs

Question 27

How may sarcoidosis present in young adults?

Answer 27

Acute arthralgia- joint pain Erythema nodosum-swollen fat under skin causing bumps Bilateral hilar lymphadenopathy

Question 28

How else can sarcoidosis, and a number of other respiratory conditions, be diagnosed?

Answer 28

Accidently on a CXR

Question 29

Define non-caseating

Answer 29

No necrosis in the middle of a granuloma

Question 30

What might you see in lymph node sarcoidosis?

Answer 30

Non-caseating epithelioid granulomas

Question 31

Name some of the antigens which may trigger hypersensitive pneumonitis.

Answer 31

Thermophilic actinomycetes- mould grown on hay Bird / Animal proteins Fungi Chemicals Others

Question 32

Describe some of the presenting symptoms in those with hypersensitive pneumonitis.

Answer 32

Fever, dry cough, myalgia, Chills 4-9 hours after Ag exposure

Question 33

What might you hear upon auscultation of someone with hypersensitivity pneumonitis?

Answer 33

Crackles, tachyopnoea, wheeze tachyopnoea= rapid and shallow breathing btw, need to try and remember this

Question 34

Describe the chronic presentation of hypersensitive pneumonitis.

Answer 34

Insidious- slowly, no symptoms at first Malaise, SOB, cough

Question 35

Which two hypersensitivity reactions are there in hypersensitivity pneumonitis?

Answer 35

Type III and Type IV

Question 36

What forms in type IV hypersensitivity reactions?

Answer 36

Granulomas

Question 37

Which cells are involved in type III hypersensitivity reactions?

Answer 37

Lymphocytes

Question 38

Which part of the lungs does hypersensitivity pneumonitis usually affect?

Answer 38

Upper zone of the lung

Question 39

When might you see someone develop UIP (Usual Interstitial Pneumonitis)?

Answer 39

-If they have a connective tissue disease -Drug reaction -Post infection -Industrial exposure e.g. asbestos

Question 40

What type of hypersensitivity reaction is associated with UIP?

Answer 40

Type II

Question 41

What is UIP defined by?

Answer 41

Patchy interstitial chronic inflammation Smooth muscle and vascular proliferation Proliferating Fibroblastic Foci -?don't really need to be concerned about this, more worried about the concept of UIP as a whole

Question 42

List some of the presenting symptoms of Idiopathic Pulmonary Fibrosis (UIP).

Answer 42

Dyspnoea, Cough, Basal Crackles, Cyanosis, Clubbing

Question 43

Is UIP progressive or treatable?

Answer 43

Progressive Most die within five years

Question 44

What does the term honeycombing refer to?

Answer 44

Fibrosis or End-Stage Honeycomb Lung i.e. non functional, shrunken, hardened lung

Question 45

Just for a recap question to finish- describe what happens in shunt.

Answer 45

Blood passes from the right to left side of the heart without contacting ventilated alveoli